For example, there is known a filling system including first and second filling machines; in the first operation mode, the first and the second filling machines fill different liquids into a vessel in turn; and in the second operation mode, only the second filling machine is used to fill only one type of liquid into the vessel while the unused first filling machine is washed (refer to Patent Document 1).
This filling system includes a bypass wheel for directly transporting a vessel to the second filling machine by skipping the first filling machine in the second operation mode. A rinser outlet wheel, which ejects vessels from a rinser provided upstream of the first filling machine and the bypass wheel, transfers vessels to a first conveyance wheel in the first operation mode and to the bypass wheel in the second operation mode.
Furthermore, in order to enable cleaning of the first filling machine in the second operation mode, a section provided with the first filling machine needs to be isolated from a section provided with the bypass wheel. Therefore, as for the structure disclosed in Patent Document 1, vessels are supplied to the first filling machine via the first conveyance wheel and a first inlet wheel, but are ejected from the first filling machine via a first outlet wheel and a second conveyance wheel. Further, a partition wall is provided between the first conveyance wheel and the first inlet wheel and between the first outlet wheel and the second conveyance wheel, whereby vessels are transferred through each of the opening provided with a shutter. Note that, when closing the opening of the partition wall with the shutter, the grippers of the first and second conveyance wheels are manually detached therefrom to avoid interference with the shutter.